Lightning diverters



Nov. 21, 1961 M. M. NEWMAN LIGHTNING, DIVERTERS Filed March 10, 1958 FIG. 3

FIG.|

FIG, 2

INVENTOR MORRIS M. NEWMAN ATTORNEYS United States Patent 3,009,982 LIGHTNING DIVERTERS Morris M. Newman, 2218 Doswell Ave., St. Paul, Minn. Filed Mar. 10, 1958, Ser. No. 720,115 Clain1s. (Cl. 174-2) The herein disclosed invention relates to lightning diverters and has for an object to provide a diverter adapted to be mounted adjacent critical areas and which will effectively serve to divert lightning away from the objects located at such areas.

Another object of the invention resides in providing a diverter particularly useful in conjunction with aeroplanes and which can be used to protect critical areas such as fuel vents and similar objects.

Another object of the invention resides in providing a lightning diverter which will not cause radio noise or interference.

A still further object of the invention resides in providing a lightning diverter which will not cause precipitation static interference and which will function as a static di-scharger for quietly discharging electrical charges collected on the metal skin of the aeroplane.

An object of the invention resides in providing a lightning diverter and precipitation static discharger which may be used on transonic aircraft.

An object of the invention resides in constructing the diverter in the form of a whip having an insulating core attached to a suitable metal mounting which in turn is secured to the fuselage of the aeroplane adjacent the critical area, and infurther forming a non-inductive resistor on said core extending from the tip to said mounting and connected to said mounting.

Astill further object of the invention resides in grading theresistance of said resistor along the extent thereof and preferably so thatthe resistance per unit length is greater at the 'tip than at said mounting.

An object of the invention resides in dividing the resistor in sections, each adjoining section having aprogressivelylesser or greater resistance than the preceding section.

Another object of the invention resides in forming the resistor as a painted layer encircling a core of insulating material.

A still further object of the invention resides in the particular construction for attaching the whip to the mounting and the mounting to the skin of the fuselage.

Other objects of the invention reside in the novel com bination and arrangement of parts and in the details of construction hereinafter illustrated and/or described.

In the drawings:

FIG. 1 is an elevational view of a lightning diverter illustrating an embodiment of the invention.

FIG. 2 is a sectional view taken on line 22 of FIG. 1 and drawn to a greater scale.

FIG. 3 is a wiring diagram of the electrical circuit of the invention.

The lightning arrester shown consists of a whip which is mounted on a mounting 11. This mounting is adapted to be mounted on a lightning dispersing surface at the locality of an object desired to be protected from lightning.

The whip 10 consists of a core 12 which is constructed I of a resilient electrical insulating material such as fiber 7 and which extend throughout the entire length of the exposed portion of the whip. The resistor 15 has the ice greatest resistance and the following resistors each have a lesser value of resistance than the one preceding. The values of the resistances preferably vary in accordance with a geometrical progression, though other types of variation may be employed. The resistors are most conveniently made by applying resistive coatings to the core in the form of a paint or by molding the resistors on the core. In each case the resistors make contact with one another so that a single resistive unit results Whose resistance varies progressively throughout its length. In actual practice, resistors varying in the rado of 10 to 1 have been found practical and the following value of resistances for the various resistors have given satisfactory results:

Megohms/squ are Resistor 15 Resistor 16 1O Resistor 17 1 Resistor 18 .1 Resistor 19 .01

It is to be noted that no metal or other highly conductive tip is applied to the free end of the whip, so that the lightning first strikes the high resistance element of the resistive unit.

The mounting 11 is in the form of a metal casting and has a base 21 with a boss 22 extending outwardly therefrom. Base 21 is formed with a surface 23 adapted to a number of holes 28 through which bolts may pass and by means of which the mounting 11 may be attached to the structure on which it is to be mounted. The boss 22 has an open ended bore 24 which is formed at its outer end with a frusto-conical socket 25. Said boss is further formed with internal threads 26 at the portion of the bore 24 which adjoin the socket 25. The axis of the bore 24 may be placed at an angle With reference to the surface 23 as shown in FIG. 2.

Theattaehed end 13 of the core 12 of whip 10 is mounted in a metal ferrule 29. This ferrule has a bore 3-1 formed in it and of dimensions to receivethe attached end 13 of the core 12. The core 12 may be cemented in place in the bore 31 or the same may be molded in place in said bore. The surface of the end 13 is roughened as indicated at 32 to procure better adhesion between the core and the ferrule. The outer end of the bore 31 is formed with an enlargement 33 in which the resistor 19 extends and by means of which the resistor is brought into firm contact with the ferrule.

The outer end 30 of the ferrule 29 is formed with threads 35 which screw into the threads 26 of the boss 22. The portion 34 of the ferrule 29 adjacent the threads 35 is provided with a frusto-conical part 36 which fits into the socket 25 in boss 22 and which makes intimate contact with the mounting 11. The resistive unit of the whip 10 is covered by an insulating protective sion occurs, the next resistor being one-tenth of the former. The charge hence follows the diverter and reaches shank 29 and mounting 11 and from which it is dispersed to the structure on which the diverter is mounted.

The advantages of the invention are manifest. The diverter may be attached to a dispersing structure adjacent an object to be protected and when so disposed diverts the lightning and protects the object. The instant invention will cause the lightning charge to enter the diverter at the free end of the whip and to flow throughout the length of the diverter and to be dispersed by the dispensing structure. The device can be constructed at a nominal expense and is simple and easy to install. The diverter will not cause radio interference and will not cause precipitation static interference and functions as a static discharger for quietly discharging electrical charges collected on the metal skin of an aeroplane. The diverter may be used on transonic aircraft.

Changes in the specific form of the invention, as herein described, may be made within the scope of what is claimed without departing from the spirit of the invention.

Having described the invention, what is claimed as new and desired to be protected by Letters Patent is:

1. A lightning diverter comprising an elongated core of insulating material, a conducting mounting to which one end of said core is attached, the other end being free, means for attaching said mounting to conducting means adjacent the object to be protected and a solid resistor mounted on said core and extending throughout the length thereof and being connected to said base, the resistance of said resistor, progressively varying from one end of said core to the other.

2. A lightning diverter comprising an elongated core of insulating material, a conducting mounting to which one end of said core is attached, the other end being free, means for attaching said mounting to conducting means adjacent the object to be protected and a solid resistor mounted on said core and extending throughout the length thereof and connected to said base, the resistance of said resistor progressively varying from one end of said core to the other and being greatest for a given distance at the free end, said resistor being divided into 'a number of sections greater than two each having a different value of resistance, the values of the successive sections forming a geometrical progression.

3. A lightning diverter comprising an elongated core of insulating material, a conducting mounting to which one end of said core is attached, the other end being free, means for attaching said mounting to conducting means adjacent the object to be protected and a solid resistor mounted on said core and extending throughout the length thereof and connected to said base, the resistance of said resistor progressively varying from one end of said core to the other and being greatest for a given distance at the free end, said resistor being divided into a number of sections greater than two each having a different value of resistance, the valves of the successive sections forming a geometrical progression and in which the section having the highest resistance is at the free end of the core.

4. A lightning diverter comprising a mounting for attachment to conducting means adjacent the object to be protected, an elongated resistor connected to, supported by and issuing outwardly from said mounting, said resistor being divided into a number of sections greater than two each having a different value of resistance, the values of the successive sections forming a geometrical progression with the section having the highest value of resistance outermost.

5. A lightning diverter comprising a mounting for attachment to conducting means adjacent the object to be protected; an elongated resistor connected to, supported by and issuing outwardly from said mounting, said resistor being divided into sections each having a different value of resistance, the values of the successive sections forming a geometrical progression, the value of the resistance of each section being ten times or more the value of the resistance of the adjacent outermost section.

References Cited in the file of this patent UNITED STATES PATENTS 361,520 Hill Apr. 19, 1887 505,106 Hodges Sept. 19, 1893 1,617,691 Van Diest Feb. 15, 1927 1,863,080 Austin June 14, 1932 2,333,144 Bennett Nov. 2, 1943 2,502,657 Lindenblad Apr. 4, 1950 2,712,602 Hallen July 5, 1955 2,927,148 Palomino Mar. 1, 1960 FOREIGN PATENTS 574,906 Great Britain Jan. 25, 1946 736,836 Great Britain Sept. 14, 1955 

